Image was everything for Liberace, the legendary pianist and singer at the center of HBO’s upcoming biopic, Behind the Candelabra, starring Michael Douglas and Matt Damon. “The most important part of show business is not the second word, it’s the first,” the performer once wrote. “Without the show there’s no business.”

Liberace’s own show—his outlandish glittering capes, sculpted face, and perfectly coiffed hair—became the stuff of legend, perhaps even overshadowing his musical talents. It would be easy for an actor playing Liberace to get lost in all the crazy clothes and prosthetic makeup, or to let the costumes do the work for him.

But Michael Douglas, who will portray the larger-than-life performer in the biopic, was determined to go beyond the glitz and glitter of Liberace’s public persona to portray his subtle musical mannerisms.

“Of course, you’re never gonna be as good as he was,” Douglas told Entertainment Weekly, but added that he had spent months taking piano lessons and watching old videos of Liberace’s performances to perfect the pianist’s body movements.

Co-star Matt Damon, who plays Liberace’s young lover Scott Thorson, told EW he was impressed from the start by Douglas’s commitment to the role.

“The moment I knew we were find was the Sunday before we started shooting. Michael had a brunch at this house, and his son sat up in front of everybody and did the entire monologue with the [piano-playing] hand movements and everything. And I thought, ‘Oh my God, I can’t imagine how much Michael has been rehearsing for his 11-year-old son to be able to actually do the thing!”

You can preview Douglas’s piano skills—and his many metallic capes and suits—in a new teaser video released by Entertainment Weekly, and you can watch an earlier teaser here: